Skip to content

Updated pre-emphasis time constant. #20

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
creeper6530 wants to merge 3 commits into
base: master
Choose a base branch
from
Open

Updated pre-emphasis time constant. #20

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
1a06dfe
Updated pre-emphasis time constant.
creeper6530 May 13, 2022
36bd285
Changet yet again to make it easier to edit
creeper6530 May 13, 2022
cd35cb8
Deleted binary, as it's outdated.
creeper6530 May 13, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Binary file removed pifmplay/pifm
View file
Open in desktop
Binary file not shown.
3 changes: 2 additions & 1 deletion pifmplay/pifm.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,7 @@

#define PAGE_SIZE (4*1024)
#define BLOCK_SIZE (4*1024)
#define PREEMP_TIME_CONST 50.0e-6 // 50us. Change to 75us if you are in USA or South Korea

#define PI 3.14159265

Expand Down Expand Up @@ -261,7 +262,7 @@ class PreEmp : public SampleSink {
// this isn't the right filter... But it's close...
// Something todo with a bilinear transform not being right...
PreEmp(float rate, SampleSink* next):
fmconstant(rate * 75.0e-6), // for pre-emphisis filter. 75us time constant
fmconstant(rate * PREEMP_TIME_CONST), // for pre-emphasis filter. 50us/75us time constant
dataold(0),
next(next) { };

Expand Down